package Demo19;

/**
 * x的最小平方根
 * https://leetcode.cn/problems/sqrtx
 * 采用二分模板,套用模版来实现解题
 */

class Solution {
    public int mySqrt(int x) {
        if(x < 1) return 0; 
        long left = 0,right = x;
        while(left < right) {
            long mid = left + (right - left + 1) / 2;
            if((long)mid * mid <= x) {
                left = mid;
            }else {
                right = mid - 1;
            }
        }
        return (int)left;
    }
}